DTC B1411 Immobilizer Antenna

DTC detecting condition:

Faulty antenna

CAUTION: When the body integrated unit is replaced, registration of the immobilizer system is required. For details, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume. Contact an Authorized Subaru Dealership.

Wiring diagram:

Immobilizer system Ref. to WIRING SYSTEM>Immobilizer System>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

CHECK BODY INTEGRATED UNIT POWER SUPPLY CIRCUIT .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from body integrated unit.
3. Measure the voltage between the body integrated unit connector terminal and chassis ground.
  Connector & terminal
  
  (i84) No. 6 (+) - Chassis ground (-):
Is the voltage 10 V or more?

Yes: Go to 2

No: Check the harness for open or short circuit between body integrated unit and fuse.
CHECK BODY INTEGRATED UNIT GROUND CIRCUIT (OPEN CIRCUIT) .
Measure the resistance between the body integrated unit connector terminal and chassis ground.

Connector & terminal

(B280) No. 1 - Chassis ground:

(i84) No. 1 - Chassis ground:

Is the resistance less than 10 Ω?

Yes: Go to 3

No: Repair the open circuit of the body integrated unit ground circuit.
CHECK ANTENNA POWER SUPPLY CIRCUIT .
1. Connect the connector to body integrated unit.
2. Disconnect the connector from the antenna.
3. Insert the ignition key into the key cylinder, then measure the voltage between the antenna connector terminal and the chassis ground.
  Connector & terminal
  
  (B415) No. 1 (+) - Chassis ground (-):
Is the voltage 5±0.5 V approx. 200 ms after inserting the ignition key into the key cylinder? And then, does the voltage return to 0 V within 2 s?

Yes: Go to 5

No: Go to 4
CHECK ANTENNA POWER SUPPLY CIRCUIT (OPEN) .
1. Disconnect the connector from body integrated unit.
2. Measure the resistance of body integrated unit connector terminal and antenna connector terminal.
  Connector & terminal
  
  (B281) No. 2 - (B415) No. 1:
Is the resistance less than 10 Ω?

Yes: Replace the body integrated unit. Ref. to SECURITY AND LOCKS>Body Integrated Unit

No: Repair the harness or connector between body integrated unit and antenna.
CHECK ANTENNA GROUND CIRCUIT (SHORT CIRCUIT TO GROUND) .
Measure the resistance between antenna connector terminal and chassis ground.

Connector & terminal

(B415) No. 7 - Chassis ground:

Is the resistance less than 10 Ω?

Yes: Go to 7

No: Go to 6
CHECK ANTENNA GROUND CIRCUIT (OPEN) .
1. Disconnect the connector from body integrated unit.
2. Measure the resistance between antenna connector terminal and chassis ground.
  Connector & terminal
  
  (B281) No. 30 - (B415) No. 7:
Is the resistance less than 10 Ω?

Yes: Replace the body integrated unit. Ref. to SECURITY AND LOCKS>Body Integrated Unit

No: Repair the harness or connector between body integrated unit and antenna.
CHECK ANTENNA COMMUNICATION CIRCUIT (OPEN) .
Measure the resistance of body integrated unit connector terminal and antenna connector terminal.

Connector & terminal

(B281) No. 10 - (B415) No. 5:

(B281) No. 22 - (B415) No. 4:

Is the resistance less than 10 Ω?

Yes: Go to 8

No: Repair the harness or connector between body integrated unit and antenna.
CHECK ANTENNA .
1. Replace the immobilizer antenna. Ref. to SECURITY AND LOCKS>Immobilizer Antenna
2. Insert the ignition key in the ignition switch. (OFF or ACC)
3. Perform the Clear Memory Mode. Ref. to IMMOBILIZER (DIAGNOSTICS)>Clear Memory Mode
4. Read the DTC of the body integrated unit. Ref. to IMMOBILIZER (DIAGNOSTICS)>Read Diagnostic Trouble Code (DTC)
Is DTC B1411 displayed?

Yes: Replace the body integrated unit. Ref. to SECURITY AND LOCKS>Body Integrated Unit

No: Antenna has a failure.